Question

Which of the following is a chemical reaction?

1- Dropping a sliced orange into a vat of Sodium Dydroxide
2-Cutting a piece of paper into two pieces
3-Filling a balloon with air
4-Freezing liquid Mercury

Answer 1

Dropping a sliced orange into a vat of sodium dydroxide

Answer 2

1- Dropping a sliced orange into a vat of Sodium Dydroxide

Step-by-step explanation:

The other answers (2-4) are only physical changes that don't change any chemical compositions.